The present invention relates to a music box, which is an improvement of the conventional technical solution for manufacturing music box.
As well known, the conventional music box comprises a frame, a spring case, a spring wound-up means, a gear train, a music drum (music cylinder), a vibrating member with comb-like seams, a speed regulating mechanism and the supports for each of the components.
In the prior art, the U.S. Pat. No. 4,458,573 has disclosed a technical solution and the exploded perspective view of which is shown in FIG. 5. This solution has several shortcomings as followed: 1) its spring case 3' and the speed regulating support 3A' are integrally molded with plastics; the overall spring case 3' includes an upper section and a lower section; the upper section (made of plastics) 3 and the lower section (made of aluminium-alloy) 27' are connected together through the holes 48', 49' (on upper section) being fired by the bosses 29', 30' (on lower section), thus, when assembled, there is a clearance on the circumferential wall where the upper and the lower sections are connected, and the window 50' formed on the circumferential wall is used for the spring (not shown) to have an end extended from inside the wall to outside, so that, the spring is capable of being firmly fixed on the wall of the spring case, however, when the spring is wound up tightly, the whole body of the spring case 3' will be deformed due to the force released by the spring; 2) since the speed regulating support 3A' and the spring case 3' are integral with each other, the deformation described above will cause directly the plane of the speed regulating support 3A' (cantilever beam structure) to be deflected, therefore, as the upper end 20b' of the speed regulating shaft 20' engages with the bearing hole 45' which is on the plane of the speed regulating support 3A', there is a great possibility for the speed regulating shaft 20' to deviate from the bearing hole 45' when the top of the speed regulating support 3A' deflects; 3) the boss 24' fitting with the hole 47' is located in such a position, which is adjacent to the front end of the vibrating member 6', and is just below the low-keys where they have their maximum amplitude, that once the music drum 2' rotates with high speed and plucks the keys violently, the low-keys and the boss 24' will interfere with each other, thus reducing the quality of the sound; 4) the damping weight part 38', similar with the conventional vane wheel structure, produces high noise in its operation; furthermore, such a structure is not capable of being connected easily by the brake means (not shown).